Scallops (River Hall, Mammoth Cave, Kentucky, USA) 4 : 無料・フリー素材/写真
Scallops (River Hall, Mammoth Cave, Kentucky, USA) 4 / James St. John
| ライセンス | クリエイティブ・コモンズ 表示 2.1 |
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| 説明 | Scallops developed on Mississippian limestone in a Kentucky cave, USA. (photo by Ljubomir Risteski)The wavy features shown here are scallops - asymmetrical, curvilinear, ridge-like, dissolutional features formed by flowing water. They somewhat resemble asymmetrical ripple marks, in that they form in a one-directional current, and the short side of each scallop represents the downstream direction.These examples are on a limestone surface in River Hall in western Kentucky's Mammoth Cave, the longest cave on Earth. The system has 412 mapped miles, as of fall 2017.Larger, longer scallops formed in slower-moving water. Smaller, shorter scallops formed in rapidly-moving water.The prominent parting through the middle of the picture is the stratigraphic contact between the Ste. Genevieve Limestone (above) and the St. Louis Limestone (below).Stratigraphy:lower Fredonia Member, basal Ste. Genevieve Limestone, upper Middle Mississippianoverupper Horse Cave Member, uppermost St. Louis Limestone, Middle MississippianLocality: River Hall (Level E), Mammoth Cave, western Kentucky, USA |
| 撮影日 | 2017-10-13 16:33:17 |
| 撮影者 | James St. John |
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